Act 1: Waterfront

If you are quick, you can grab a melee weapon off the table of weapons at the beginning of this episode. Head up the ramp and you'll encounter your first infected.

Look out for the zombies dressed in riot gear -- their heavy shielding makes them very, very difficult to kill with melee weapons or bullets. To kill them, you need to hit them in the back.

Head through the door under the Waterfront Market sign. Hang a left and move down the street towards the overturned vehicles.

A ramp on your left will take you above the vehicles. Drop down on the other side and make a right past the café with the jukebox in it (Pro Tip: You can play a few songs by approaching the jukebox and activating it -- one of them is a Jonathon Coulton song called "Re: Your Brains." He's the dude who wrote "Still Alive" from Portal, also rumored to be available in the jukebox...).

Look for a path on your right leading to a back lot with a barrel on fire in the corner. Enter the door next to this barrel.

Head through the double doors of the kitchen into the dining area. Exit onto the street and turn left. The safehouse is across the street at the fence.